With the popularity of cameras, there are more and more photography enthusiasts and professional photographers as well. For these photographers who take photos of outdoor scenes such as flowers, animals or nightscapes, they usually require to use tripods with extended legs for taking photos of these objects from high visual angles. However, it happens that a tripod loses balance easily when the extended legs are to be extended or when large photographic equipment is supported by the tripod, thereby causing a risk of photographic equipment to be damaged.
In order to prevent a tripod from being collapsed or from being shook caused by unstable center of gravity of the tripod, in conventional arts, a tripod needs to install a fixing device for supporting purposes, where the fixing device is usually installed at a position near the bottom of a tripod so as to keep the tripod legs steadily opening in their most degree such that the tripod can stably stand on the ground. However, the fixing device is heavy and inconvenient for carrying. Furthermore, there is some other drawback for the prior tripod that the fixing device needs to be installed and dismantled through some complicate processes before and after each usage. Therefore, it is necessary to improve the conventional tripods.